Automatic telephone-exchange system.



C. L. GOODRUM.

AUTOMATIC TELEPHONE EXCHANGE SYSTEM.

APPLICATION FILED APR.26.1915.

^ 1,281,348. Patented 0@f.15,1918.

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AUTOMATIC TELEPHONE EXCHANGE SYSTEM.

nPPLlcArloN man M126, |915.

1,281,348. Patented oct. 15, 1918.

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AuoMMlc TELEPHONE EXCHANGE SYSTEM.

APPLICATION FILED APR. 26, |915.

` Patented Oct. 15, 1918` 6 SHEETS-SHEET 3.

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AUToMATIc TELEPHONE EXCHANGE SYSTEM.

APPLICATION FILED APR. Z6, 1915.

LQSLM@ Patented oct. 15, 1918.

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C. L. GOODRUIVI.

AUTOMATIC TELEPHONE EXCHANGE SYSTEM.

APPLICATION F1150 AP11.2s.1s15.

192m 34%, Pamed 001.. 15, 1918t 6 SHEETS-SHEET 5.

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AUTOMATIC TELEPHONE EXCHANGE SYSTEM.

APPLICATION FILED APR. 26,1915. 1,281,34. Patented 066.1519155 6 SHEETS-SHEET 6.

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y finders are released. .Thus no grou lll STATES PATENT-ll lllQlllt GHARLES L. GOODRUM, F NEW YORK, N. Y., SSIGNOR, BY MESNE ASSIGNMENTS, T0 WESTERN' ELECTRIC CUMEANY, INCORPORATED, .A CORPORATION 0F NEW' YORK.

AUTQMATIC TELEPHONE-EXCHANGE SYSTEEV.

Specification of Retters Patent.

Patented @et T15, MMS.

Application med April 2G, MM5. Serial No. 23,827.

To all whom t may concern:

Be it known that l, CHARLES L. GooorUM, a citizen of the United States, residing at New `York, in the county of New York and State of New York, have invented certain new and useful llmprovements in Automatic TelephoneEXchange Systems, of which the following is a full, clear, concise, and exact description.

This invention relates to telephone enchanges employing machine switching, and particularly to such systems wherein calling lines terminate in passive contacts in automatic finder switches hy means of which they are extended.

@rdinarily the lines are divided into groups, each group being served hy a group olf-ndere to which they are multipled. "lhe number of finders provided is usually inst sufficient to take care of the maximum nurnher ci simultaneous calls. li, however, an abnormally large number of calls occurs in any one group, those in excess of the numher finders are compelled to wait until busy could, with the previous arrangements, set more connections than there inders allotted thereto, unless surplus common to the groups were provided.

This invention contemplates providing a circuit arrangement whoicc-y each group may share its iinders with an adjacent group, thus rendering possible *under certain conditions namely, in case a particular group initiates an abnormal number of calls,

to have these calls completed by finders horrowed jfrom an adjacent gro-up. then, such adjacent group has need of more finders than remain, the arrangement is such that it can borrow iinders of the succeeding group, and so on, experience showing that it an abnormally large number of calls is initiated in one group, it is very improbable that the succee ling groep is initiating enough calls to utilize all the hinders allotted thereto. By virtue of this invention there fore excess calls are talren care oli without the necessity of providing surplus ndere.

The invention will he clearly understood when considered with regard to specic embodiment thereof.

ln the drawings, Figure i shows all o the apparatus individual to one suoscriherf's line and a portion of 'the apparatus individual to another inthe same sub-group, and apparatus lcommon to the sub-group in which thesey two lines belong, that individual to the lines being shown to the left and that coinmon to the sub-group to the right of the dotted line; Fig. 2 shows a line linder and a rst selector with their associated circuits and apparatus; Figs. 3 and a together, show the starter wire circuit arrangement for apportioning the ndere among the subgroups, the terminal panel beingv shown schematically at the top of the sheet; Fig. 5 is a schematic representation of a terminal panel arranged in accordance with this invention; and Figs. 6 to 9 inclusive are views ci a linder switch structure suitable for use with this invention; F ig. 6 is a side elevation partly in section; Fig. is a section on line '2-Y ci' Fig. 6 showing the switch at the too of the finder which chooses the sub-grou@ containing the calling line; Fig. 8 is a section on line 8-8 of 6; l? ig. 9 is a section on line 9-9 of F ig. 6.

The switch structure shown in Figs. 6 to inclusive will first he described.

The panel may he made up according to "1 e process disclosed 1n Patent 527,7l1l. lt i composed of strips of metal i) 595i and interposed insulating strips i. Each metal ic stra:l 50@ has ears projecting -rom opposite faces of the panel and adaptto he wiped overlay the brushes off the .tornatic iinder switches. Three of these sheets 50G are apportioned to each line.

Sets of terminals 225, 226, one belonging to each of three adjacent strips 500 oit a given line, are adapted to he engaged hy sets of brushes 22l, 222, 223 of line Vfinder switches, to extend said line to the connecting circuits to which such dri-ders belong.

'ihe panel or hanli is divided horizontally hy metal hars 50S into ten divisions of ten lines each.. Thus each vertical row is divided into ten sections. Each such section is served ,hy a set ont' brushes 221, 222, 223 adapted to engage with. the sets olf terminals 22e, 225, 533% thereof. The of brushes serving a given vertical row are mounted upon supports 508 which are in turn rigidly mounted upon a common carrier or rod 507. The sets brushes are spiially arranged upon the rod and the rod may he rotated hy a magnet ci? 'to position the proper set of brushes heiow the desired section. of the vertical row the calling line is' tcnnected throng..

normally just helovv multiples ot said lines,

whereby no primary sub group choosing movement is necessary in case it is started oy a calling line in the sub-group to which it is allotted. Since, as will appear, a number of linders are accessible to a number of suhgroups, the circuit arrangement is such that it the finder normally assigned 'to any suhgroup is lousy, another inder will he set in motion Joy the initiation of a call in such sub-group to connect 1with the terminals of such line. :in this event the hrush rod 507 of such iinderv is given arotary movement to -position the brush serving 'the section oli the vertical row, containing multiples of said lines, below said section, and thereafter a vertical movement to connect 1with the callline in such sut-group. lior this purpose a switch G is located at the top ot each linder. Each euh-group or' lines is represented on this switch hy a metallic segment s. '.lhese segments are adapted to loe wiped over oy an arm o hated to the brush rod 507, but suitably insulated therefrom. 'lhe initiation of a call in any sub-group electrically distinguishes the segment s individual thereto on the switch so that When the brush a reaches such segment a circuit change is brought 'about to stop such movement, and the relation between the arm o of each rod 507 and its sets of brushes is such that when said arm has reachedthe segment in question, the set of crushes belonging to this line sub-group is positioned just oelow the section containing multiples oit such lines. The upward movement of the rody507 causes the said set of brushes Wipe over the sets of terminals oil" this section .until that of the calling line is reached, when a circuit change is produced to stop such movement, whereby this inder to selector, which is then controlled from the sender at the substation to entend toe connection either rectly. a connector, orin 4case oi? a iirst through series selectors.

ln the the thereof, necessary :tor a comprehension of 'this invention, will loe given.

, brush rod 50'? is provided near its lower end with a gear Wheel 512. The pavvl. 516 of the armature SlT/.ot rotary magnet 205 does not act directly upon the gear Wheel 512 of the rod, lout steps around a rotary member 5l9 by engaging a ratchet 'Wheel 521 thereon, which member carries a second gear Wheel 520 which meshes with the 2gear Wheel 512 on the rod 507. After the brush rod 507 has heen rotated hy said magnet to the proper point,`the rotary magnet ceases to operate. The rod is then elevated by the pavvl carried hy ,armature 523 of vertical magnet 20'? mounted upon the frame 5M.

Upon the beginning of the upward movement of the brush rod 50?', a spring 525, secured to the trame, moves upwardly, a pin 526 thereon entering a notch in the gear Wheel 520 to prevent the member 519 from i being,` restored loy the spring 527, when the'l dog 528 is Withdrawn later,this dog and the dog 529 of the vertical ratchet being re` leased kupon the termination ot the conversation hy the attractive movement oi" the armature ot a release magnet (not shown).

'l/lf hen such release magnet is energized, the hrush rod 507 drops, due to the Withdrawal of dog 529. W hen it reaches its low-j ermost position the shoulder 532 on the lorush;v rod 507 presses'the sgoring 525 against its mounting plate 533. The consequent Withdrawal of the pin 526 'from the gear Wheel 520, permits the spring 527 to rotate the member 519, `whereupon the'gear Wheel' 520 105 restores the brush rod 50i to normal position.

Referring new to Figs. l and 2, a detailed description of the opera-tion involved in connecting a callingr line with a tiretl selector through the intermediation of the iinder just ,described will render more comprehensible a consideration of Figs. 3, land 5.

l Referring now to Fig. l the substation shown is assumed to he that of line No. l5.,

in tl e second euh-group of ten lines, and the nder allotted thereto is the seco-nd, n 3, 5). The line conductors lil, 'i12 ot wx. s line-terminate in a' pair r. l'

22st, ot the inder shown in 6 to 0. The test terminal 226 or this e is cenhy conductor lle vili e cutoi 11.20 c25 such linea subscribers ce 'with raeraae moves his receiver, a circuit is closed for the line relay 116, said circuit leading over the line conductors 111 and112 and through hand winding of line relay 116, left-hand armature and back contact of the cutoff relay 120, conductor 121,v contacts 117, 118,

'conductor g2, left-hand armature and back contact of relay o2, conductor 2, relay c2 to ground. Relay c2 thereupon locks itself up in series with the line relay 116 in a circuit leading through its left-hand armature and front contact, said circuit being independent of relay 02. Assuming that the line finder normally associated with this sub-group be idle, relay c2 at its right-hand armature and front contact closes a circuit for the escapement magnet 217 to move .the side switch of such line finder into position 2 to be in the upward movement of the brush ro to cause the set of wipers of this line sub-group to test for the calling line. Under such assumption the arm a2 ,of the finder brush rod is in contact with metallic segment No. 2 individual to this line sub-group (as shown in Figs. 2, 3). This circuit is as follows: free pole of battery, primary magL net 205 (Fig. 2), conductor 212, side switch escapement magnet 217 conductor 218, arm 216, conductor 215, brush a2 of the sub-group switch of the finder, segmentl No. 2, individual to ythis sub-group, conductor 11,2,

right-hand armature and front Contact of relay c2 to ground. Although the relay c2 establishes a circuit for the energization of slow acting relay b2, which through its .right-hand armature grounds the conductor e2 and apparently shunts the escapement magnet 217, it should be noted that this action does not in reality take place, for by the time that slow acting relay b2 can establish a ground on conductor e2 it is broken at the arm 210 through the immediate action of the escapement magnet. Theprimary magnet 205 is so adjusted and the circuit conditions are such that it does not operate when this circuit is closed. The escapernent magnet 217 is however :energized and is so constructed that' it releases the side switch to position 2 upon its energization, in which. position the circuit for the said magnet 217 is maintained, this circuit lbeing es follows: free pole of battery, mag- .net 205, conductor 212, escapement magnet 217, conductor 218, arm 216, now in position 2, conductor 287, conductors 202, m2, side switch arm d2, conductor e2, right-hand armature and front contact ciE relay b2, conductors ft2, i2, right-hand armature and front contact relay c2 to ground. .The

slow-acting relay h2 was energized. upon the energization of relay c. rlhe arm 210 of the side switch inxposition 2 closes a circuit for secondary magnet 207, which by interrupting its own circuit, raises the brush rod,

during which movement the set of brushes second contact, conductors 209, 208, arma-- ture and back contact of magnet 207, conductors 268, 266, right armature and front contact of escapement magnet 217, conduc tor 267, conductor 204, armature and back contact of release ma net 203, conductors 8o 202, m2, arm d2, con uctor e2, right-hand armature and front contact of relay 52, conductors k2, Z2, right-hand armature and front contact of relay c2 to ground.' When the finder brushes 221, 222 and 223 arrive 85 upon the terminals 224, 225 and 226 of the line of subscriber 15 initiating the call, the cut-off relay 120 of such line is energized over the following circuit: free pole of battery, relay 120, conductor 114, terminal 226,

brush 223, conductor 113, contacts 228, 270 of magnet 217, conductor 271, resistance 272, conductor m2, arm d2, conductor e2, righthand armature and front contact of relay b2, condutcors k2, Z2, right-hand armature and contact of relay c2 to ground. Cutoff relay 120 at its left-hand armature opens the circuit of relay c2, which in de'energiz- .ing opens the circuit of driving magnet 207, the finder being thus brought to rest upon 10o the calling line terminals, and held there by holding pawls 528, 529 (Fig. 6). When the cutof relay 120 operates and denergizes the relay c2 the escapement magnet 217 also is denergized, and its armature in retracting is arranged to release the side switch into position 3. The closure of contacts 228, 229 of magnet 217 places ground on the multiple test terminals of this line, whereby connection cannot be made to it by a connector. In.

this-position the arms 232 and 233 of the side switch connect the line conductors 111, 112 through to the line relay 234 of the selector. It will, of course, be understood that the operations involved in connecting 115 the calling line with a connecting circuit just traced take only a fraction of a` second. The operation of setting the selector will not be described since it forms no part of the invention. y

Referring now to Fig. 5, this gure repl resents diagrammatically a panel or dat faced bank, wherein multiples of three groups of lines of one hundred each terminate. lines each shown in Figs. 3 and 4, and thirty in Fig. 5. As shown in Fig. 5, the lines are slipped in sub-groups, that is multiplies or each sub-group appear before and ac- There are twenty sub-groups or? ten 1205 .n resinas groups are served by the same set oit linde ers. This will be evident from a study of the. said figure. Thus, lines 0-9 are accessiblc to the ten elevators or brush carriers numbered 1 to 10. Lines 10 to 19 skip inder Xo. 1, begin to appear in finder No. 2 and drop orf at finder No. 11, and so on.

Referring` now to Figs. 3 and fl, these iig! ures show the starter wire arrangement. By reference to these figures and bearing in mind what has been said. it is evident that upon the initiation ot a call from any subgroup of ten subscribers, since each such sub-group has an-elevator or finder normally serving the same, and in position to move its brushes over the terminals thereof in the panel, no preliminary rotary movement of the elevator or brush rod of such finder to pick out this sub-group is necessary. ln case, however, such iinder is busy, the finders being controllable from all the lines to connect to multiples or' the lines which appear before them. this sub-group is associated by an extended starter wire with the next idle inder, which in a preliminary rotary movement of its brush rod 50i'. positions its set ot brushes 221, 222, individual to such sub-group belor.Y multiples thereof and in a secondary verticalL movement connects with the terminals 221i, 225, of the calling line therein. it will be apparent from a study of Figs. 3, e and 5 that the iinder normally associated with a given sub-group or ten lines is the one wherein multiples of such lines begin to al pear on the panel.

rll-.is will be clear from an example. onsider the second finder (Figs. 3 and 5) which is allotted to the ten subscribers 10-12 to which the substation (shown in Fig. l), belongs, is busy, and that finders Nos. to 10 inclusive are also busy, and that a second call comes in from this sub-group. Line relay lll of such line is energized by the removal or the receiver at the substation ther of and closes the following circuit to energize relay 02: ree pole of battery, lett winding of line relay 131, armature and back contact or theJ cutoi" relay 132 of this line, contacts 117', 118', conductor 100, contacts 118, 119 of relay 110, conductor g2, lett armature and back' Contact of relay 02, conductor i?, relay c: to ground. litelays c2, b2 are energized, as before to ground conductor e2 connected to side switch arm d2 (Figs. 3, 2). This arm, however, is now in engagement with its third contact, and starter wire e2 is extended by said side switch arm to conductor ,f2 (Figs. 3, 2), armatures and back contacts of the relays b oit the linders 3 to 9 of intervening sub-groups, through armatures and back contacts of relay 1@ of the sub-group to which inder No. 10. is allotted to side switch arm d10 thereof, now in position 3, starting conductor ,tw arman tures and bach contacts of relay l2 to side switch arm al ol' finder No. 11, allotted to the subgroup containing lines 100 t0 109, of thc second group of one-hundred lines, which arm will be assumed to be in engagement with its irst contact connected to conductor m (corresponding to conductor m2 of Fig. 2) which leads tc the primary magnet 205 of such finder. This circuit may be continued.l therefore by reference to Fig. 2, and assuming the finder shown therein to be finder No. 11 of Figs. e and 5, the group test switch G11 or" which finder is shown as the last of the series at the bottoniL of Fig. 2.

lontinuing the circuit therefore by reference to Fig. 2 it leads by way of conductors m2, 202 or nder No. 11, armature and back contact of release magnet 203.l conductor 20%, armature and back contact or primary stepping magnet 205, conductor 266, conductor 268, armature and back contact of secondary stepping magnet 207, conductors 208, 209, side switch arm 210, conductors 275, 212, primary stepping` magnet 205, to ,tree pole or" the battery. IThe magnet 205 ot such inder makes and breaks this circuit,

this rotating' its brush rod 50'?, (Fig. 6).-

'lhe energization or' the sub-group relay c2, (Figs. 1 and 3) grounds conductor h2 which is inultipled to sub-group switches G- of finders 2 11 inclusive, (Figs. 2 to el). When the test brush o: of the sub-group switch G11 ot line finder llo. 11 therefore engages sub-group test segment No. 2 at' which time the set of brushes 221, 222, 223 (Figs. 6 and 8) individual to this subgroup on the brush rod 50iT of this under, is

`in operative relation to multiples et this sub-group in such under (Figs. 2 and 4;), in. this case nine rotary steps being necessary, a circuit is closed for the escapement magnet 217' oit such under to open the stepping circuit'oi rotary magnet 205. rlhis circuit may be traced by reference to 2 as follows, still assumingl the iinder circuit shown in Fig. 2 to be that or under No. 1l.. Ground, armature and v:front Contact of relay c2 (Fig. 1), conductors Z2, h2, segment number 2 of subgroup switch G oit' nder- No, 11 (Fig. 2), arm a of such switch, conductor 215 thereof, arm 216, conductor 2118., side switch escapement magnet 217, con ductor 212, primary magnet 205 to the free pole of battery. rlllre escapernent magnet in energizingn moves its side switch to position 2, as previously described to open the primary stepping` circuit and close the secondary stepping circuit. Side switch arm 210 in this position closes the circuit or Secondary stepping magnet 207, whereupon the inder is moved upwardly by said magnet, in Search of the calling line.

As set forth in the operation or setting up a connection, test brush 223 (Fig. l)

ree

during the vertical movement of the finder is connected to conductor e2, grounded at this time by the right-hand armature and front contact of sub-group relay c2 by way of arm d2, conductor m2, resistance 272, contact 270, 228 of magnet 217 and conductor 113. Thus when the calling line is reached and its cutofi1 relay 120 operated, it opens at its lefthand armature and back contact the circuit ofsub-group relay c2, as before, which in releasing, removes ground from conductor.

c2. Side switch escapement magnet 217 thereupon is denergized and releases the side switch into position 3, and the calling party is extended through to the first selector associated with finder No. 11 by side switch arms 232, 233 thereof.

While for simplicity, the segments ot .subgroup test switches G of the finders shown in F ig. 4, (belonging to the second hundred lines), are multipled to the sub-group test switches Gr of Fig. 3 of the finder of the first hundred lines, in actual practice the subgroup test switches G of Fig. d would be multipled to the sub-group switches G ot' thefinders of the next succeeding hundred, and the sub-group test switches G of the finders of the last hundred would be multipled to those of the first hundred. This will be apparent from Fig 5.

While the invention has been illustrated as embodied in av finder circuit arrangement for extending calling lines to first group select-ors, it will be understood that the invention is not so limited, but is just as applicable to systems wherein calling lines are automatically distributed to operators positions.

,combination with lines divided into groups and sub-groups, automatic finder switches arranged in groups, one of said finders being normally associated with each said subgroup of lines, sub-groups of lines from a plurality of said groups of lines appearing in multiple terminals in finders of a plurality of groups of finders, means for causing said finders automatically to hunt for a sub-group containing a calling line by a primary movement and for a calling line by a secondary movement, and means for causing one of said finders to hunt for a calling line by only a secondary movement when said calling line is in the sub-group to which said finder is normally associated.

In a tele-phonev exchange system, the combination with lines divided into groups and sub-groups, groups of automatic finder switches wherein said lines terminate in multiple contacts. saidniultiplcs being progressively slipped in said inders by subgroups, whereby multiples of a plurality ot sub-groups of each group can be connected to by finders ot a plurality ot groups, a starting conductor for each sub-group normally associated with the finder allotted thereto, a group test switch associated with each finder having a segment for each sub-group of lines, means actuated in case said finder is busy for extending said starting conductor to the next idle nder. whereby in case the finder normally assigned to a subgroup is busy, the closure ot' the starting circuit causes the group test switch of said idle finder in a primary movement to test its group segments for the calling line group te position a brush in operative relation thereto, and means for thereupon giving the iinder a secondary movement to connect with the calling line in such group.

4. In a telephone exchange system, the combination with lines divided into groups and sub-groups, groups of automatic finder switches wherein said lines terminate in multiple contacts, said multiples being progressively slipped in said finders by subgroups, whereby multiples of a plurality of sub-groups of each group can be connected to by finders of a plurality of groups, a starting conductor for each sub-group normally associated with the finder allotted thereto, said finder having a brush positioned to move directly over multiples of such sub group and having other brushes individual to the other line groups, a group test switch associated with each finder having a segment for each sub-group of lines, means actuated in case said finder busy for extending said starting conductor to the next idle finder,

whereby in case the finder normally assigned to a sub-group is busy, the closure of the starting circuit causes the group test switch of said idle finder in a primary movement to test its group segments for the calling line group to position a brush in operative relation thereto, and means for thereupon giving the finder a secondary movement to connect with the calling line in such group.

5. In a telephone exchange, automatic finder switches, lines arranged in'groups and sub-groups and appearing in terminals ot a plurality of said switches, each sub-group of each of said groups being progressively slipped to appear in a different plurality of said switches, a finder starter circuit for each said sub-group, and means under con trol of said circuit for starting a single one of said switches in Search of a calling line.

6. ln a telephone exchange system, telephone lines .arrangedl in groups, automatic finder switches less in number than the number of lines, each said group of lines having terminals in a plurality of said switches and in a diEe-reiit plurality of said switches than any other of said groups of lines and each said switch having in its terminals a plurality of said groups, a finder starter circuit for each said group of lines, and means under control of said circuit for starting a single one of said switches in search of a calling line.

7. ln a tclephpne exchange, automatic finder switches, lines arranged in groups, each' said group appearing in terminals of a plurality of said switches and each said switch having in'its terminals Ya difcrent plurality of said groups of lines, a finder starter circuit Jfor each of said groups of lines, and means under control of said circuit for starting said switches individually.

8. ln a telephone system, lines arranged in groups, automatic linder switches for extending said lines, each said group of lines having terminals in a different plurality of switches and each said switch having in its terminals a di'erent plurality of said groups. v

9. ln a telephone exchange, lines arranged in groups, automatic finder switches for. ei: Atending said lines, each said grou of lines having terminals in a plurality' o switches and each said switch having in its terminals a plurality of said groups, said groups being continuously and progressively slipped in said switches.

10. In a telephone exchange, lines arranged in groups, automatic nder switches for extending said lines, each said group of lines having terminals in a plurality of switches and each said switch having in its terminals' a plurality of said groups, all of said groups being progressively slipped in said switches. o

ln witness whereof, l hereunto subsciilual my name this 24th day of April A. D., 1915.

CHARLES L. GOODRUM. 

